I've always used a mixture of valerian root, chamomile and scullcap to induce relaxation for my patients (former chiro here). And valerian root is a great relaxant to sooth female complaints; for this herb has been used by women for such ailments since the middle ages.

I often enjoy a cup of lemongrass and ginger root. I find that it's very soothing on the stomach and helps me settle down. The warm, spicy, lemon flavour is always a great comfort to me, and it's a great cup to snuggle up and watch TV with.

If it's been a long day and I'm all achy, then I have some honeybush mixed with lemongrass usually. Honeybush is a natural muscle relaxant that's lovely and fruity. Perfect for getting me to gear down.

Sometimes if I'm really dopey, I'll add some chamomile to my lemongrass and ginger to totally zonk me out. If I want a bit of a kick without being all wide-eyed and hyper, I'll add a teaspoon of peppermint to the mix, instead of chamomile. It's a great refresher, and it makes a wonderful iced tea (add a few pieces of hibiscus for blast of colour and some vitamin C).

Chamomile is pretty interesting. It contains a considerable quantity of tryptophan.

In normal individuals, that has a calming effect.

However, in those who have hypersensitivity to the effects of cortisol (a genetic issue) OR produce too much cortisol (caused by poor feedback control, either genetic in origin or induced from chronic stress aided by periods of inactivity and poor diet), chamomile worsens the negative effects of cortisol excess or hypersensitivity.

When I am feeling like I need to de-stress I take L-tryptophan tablets, drink kava kava tea or skullcap works. Unfortunatly I am allergic to chamomile tea, but that would work really well mixed with the skullcap for your friend.

Skullcap is pretty amazing stuff, it works great in the pills from natures way

I would say the best tea for de-stressing is really any tea you like. Personally, my stress melts away as soon as I stop and have a fresh cup of a tea that I enjoy. Whether that is Black, Green, Oolong, ect; It doesnt matter to me. I just have to enjoy the cup.

For a 1-2 de-stressing punch, Chamomile works to help you relax which could in turn help with stress.